The Information Commissioner's Office will not take a complaint about a Conservative MP using unethical methods to spy on his constituents any further.

The ICO said last week that it would look into Justice Minister Jonathan Djanogly's actions following a complaint by Labour MP John Mann.

It emerged last year that Mr Djanogly had hired private detectives to spy on local party members. Mr Mann said that his conduct was improper and accused him of accessing personal information covered by the Data Protection Act.

But the MP for Huntingdon, the son of Nottingham philanthropist Sir Harry Djanogly, has always denied doing anything wrong and stated that all information was obtained legally. In response to last week's complaint he said the ICO had no relevance in the matter.

The ICO said it did not consider it necessary to take Mr Mann's complaint forward.

"The matters raised by Mr Mann do not appear to represent recorded personal information as covered by the Data Protection Act," said a spokesman. "A potential breach of section 55 - the Act's 'blagging' offence - does not therefore arise."

Mr Djaongly said he was pleased the ICO had dropped the case. He said there were no grounds for an inquiry and described Mr Mann's claim as "politically-motivated".