Police investigating the disappearance of Claudia Lawrence have arrested a man on suspicion of murder.
A man in his 50s, from York, was arrested this morning, North Yorkshire Police said.
Miss Lawrence was 35 when she disappeared six years ago in York on March 18, 2009.
Police said the York University chef's body has not been found.
A police spokesman said searches are being carried out in relation to the investigation, and are expected to carry on for a number of days.
Miss Lawrence's family have been informed of the development, police added.
A 46-year-old man arrested by officers investigating the disappearance of Claudia Lawrence has been bailed.
The man was earlier arrested on suspicion of perverting the course of justice.
Police have begun drilling inside a pub in York, as part of an investigation into the disappearance of chef Claudia Lawrence.
The Acomb pub was the focus of intense activity today by North Yorkshire Police, who also confirmed they had arrested a 46-year-old man on suspicion of perverting the course of justice.
It is understood the search of the pub is related to the arrest.
In the afternoon, a police crime scene officer left carrying drilling equipment in a case.
Today's activity took place about three miles from Miss Lawrence's small house in the Heworth area of York.
The father of Claudia Lawrence hopes today's arrest of a 46-year-old man by police investigating her disappearance "is another vital piece in the jigsaw", his spokesman said.
Police investigating the disappearance of Claudia Lawrence have been searching a pub in York since early this morning.
Several police vehicles containing dog handlers and specialist teams have been searching the Acomb which is around 3 miles from where Miss Lawrence lived.
Miss Lawrence was last seen on 18 March 2009 after leaving work at the city's university.
A 46-year-old man was arrested this morning by police investigating the disappearance of Claudia Lawrence.
The man, who was arrested in the York area, was arrested on suspicion of perverting the course of justice, North Yorkshire Police said.
Police in York investigating the disappearance of Claudia Lawrence have arrested a man on suspicion of perverting the course of justice.
The 46-year-old man is currently being interviewed in custody while searches and forensic enquiries are conducted in relation to the investigation.
A 59-year-old man arrested in May remains on police bail as enquiries continue.
North Yorkshire Police said there is a "possibility of further arrests" in the case of missing chef Claudia Lawrence.
"As investigations continue with the possibility of further arrests to be made, all sections of the community and the media are reminded and encouraged to respect the rights of others, including those connected to the case," the force said in a statement.
"To date, nobody has been charged with any criminal act emanating from this case," police stressed.