Keith Vaz, the Labour MP for Leicester East, has denied any wrong doing in connection with £500,000 payments received into his bank account.
A newspaper alleges that a police investigation at the time found the dealings to be suspicious.
As delegates look forward to Ed Miliband's big speech this afternoon, the Keith Vaz affair is overshadowing events somewhat.
It relates to an investigation uncovered by a national newspaper which says that more than 10 years ago police found payments into Mr Vaz's bank account which they considered "possibly suspicious".
Mr Vaz denies he has questions to answer following the allegations:
– Keith Vaz MP
"It isn't half a million pounds, if you look carefully at my website, look at the report, it is the sale and purchase of property."
On that website he makes it quite plain, he says "my finances were discussed by every newspaper in the country for three years and were the subject of extensive examination. I have no outside interests."
He concludes the payments into his bank account were not suspicious.
Andrew Bridgen, the Conservative MP for North West Leicestershire wants further investigation into this by the Parliamentary authorities.
Meanwhile in Manchester delegates are looking ahead to Ed Miliband's speech in which he will try to reach out to new supporters putting himself forward as a potential Prime Minister.