Police investigating the murder of a family of four killed in their home in Northamptonshire are renewing their appeal to find the killer.
A close friend of a family stabbed to death in their home has criticised detectives saying more should have been done to catch their killer.
A report into the way Northamptonshire police handled the case of a family of four murdered in their own home, is due later.
Police say they've had a breakthrough in the hunt for a man suspected of murdering a family from Northampton last year.
They have travelled to Spain, saying they believe Anxiang Du escaped to Morocco after the deaths of Jifeng Ding, his wife Helen, and their two daughters - Neil Bradford reports.
Northamptonshire Police say officers have travelled out to Madrid in Spain as part of the Ding family murder investigation. They say they believe the prime suspect Anxiang Du, who is from Coventry and has a business in Birmingham, is in Morocco.
– Detective Chief Inspector Tom Davies, Northamptonshire Police
"We now strongly believe Anxiang Du left the UK soon after the murders and travelled from Victoria bus station, London on a coach to Paris, Gallieni. After this he travelled through France into Spain - most likely through the use of public transport. His final journey was to Algeciras in Spain where he caught a ferry from there into Tangier, Morocco.
"We believe that having made his way to Morocco, Mr Du is still there and may still be in the Tangier area."
"We have been working with the Serious and Organised Crime Agency, Interpol and Crown Prosecution Service International to ensure we have the support of international law enforcement agencies who are currently focused on locating Anxiang Du in Morocco.
"We're currently working with a number of agencies including Spanish Authorities to ensure that Mr Du does not use any other routes to travel into Spain, where we know he has previously travelled to on holiday. We're also urging those who are using or will be using the ferries from Algeciras, Spain to Tangier, Morocco to be aware of our manhunt.
Police investigating the murder of a family of four have increased a reward for information to find the main suspect to 25 thousand pounds.
Chinese businessman Anxiang Du from Coventry hasn't been seen since the deaths in Northampton last April.
Police hunting for the main suspect following the murder of a Northampton family have increased the reward for information which could lead to his arrest to £25,000.
Jifeng Ding, his wife Helen Chui and their two daughters were killed in Wootton on the 29th April 2011.
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Police are increasing the reward for information about the murders of a family of four in Northamptonshire to £25,000.
Jifeng and Helen Ding and their two daughters, Alice, 12, and Xing, 18, were stabbed to death at their home in Wootton, in May last year.
Police have named Anxiang Du, who has not been traced, as the main suspect in the case.
Four people are on bail on suspicion of conspiracy to assist an offender.
Police investigating the deaths of the Ding family of four in Wootton, Northamptonshire in April last year, arrested a 22-year-old woman from Southend, Essex.
The arrest was made in Plumstead, London on suspicion of conspiracy to assist an offender.
She was interviewed and later released on police bail.
Three people who were arrested on Wednesday, also on suspicion of conspiracy to assist an offender, have also been released on police bail.
They are a 54-year-old woman who was arrested in the Radford area of Coventry, a 39-year-old woman arrested in Gloucester town centre and a 25-year-old man arrested in the Islington area of London.
Police have made a further arrest in connection with the investigation into the deaths of four members of the Ding family in Northamptonshire last year.
A 22-year-old woman from Southend, Essex, was arrested this afternoon in Plumstead, London, on suspicion of conspiracy to assist an offender.
Three people who were arrested yesterday also on suspicion of conspiracy to assist an offender have been released on police bail.
Three people arrested yesterday on suspicion of conspiracy to assist an offender in connection with the Ding family murders have been released on police bail.
University lecturer Jifeng Ding, his wife Helen and their two daughters were found stabbed to death in their home in Northampton on May 1.
The 54-year-old woman who was arrested in Coventry, the 39-year-old woman arrested in Gloucester and the 25-year-old man from Islington in London were interviewed at police stations yesterday.
Three people have been arrested today in connection with the investigation into the deaths of a family of four in Wootton, Northamptonshire.
Jifeng Ding, who was 46, Helen Chui, who was 47, and their daughters Xing, aged 18, and Alice, aged 12, were murdered at their home in April last year.
A 54-year-old woman was arrested in Coventry, a 39-year-old woman was arrested in Gloucestershire and a 25-year-old man was arrested in London.
All three have been arrested on suspicion of conspiracy to assist an offender in connection with Operation Nene.
They will be interviewed in local police stations to where they were arrested.
The arrests were made as part of a joint operation involving the local forces and the East Midlands Special Operations Unit Major Crime team.