Rochdale MP Simon Danczuk is to be investigated over expense claims for accommodation by the Independent Parliamentary Standards Authority (IPSA). The authority launched the investigation following a complaint from a member of the public.

Danczuk, who is already suspended by the Labour party over separate 'sexting' allegations, is being investigated over supplementary expenses to cover the cost of his children living with him.

He has four children in total – two children with his first wife Sonia Rossington, and two with his second wife Karen Danczuk with whom he recently separated. The MP is believed to have claimed thousands of pounds in additional expenses so he could accommodate them at a London flat, but questions have been raised about how often his two eldest children stay with him.

An IPSA spokesperson said: "Following receipt of a complaint from a member of the public, the Compliance Officer for the Independent Parliamentary Standards Authority has today opened an investigation into claims made under the MPs' Scheme of Business Costs and Expenses ('the Scheme') by Simon Danczuk MP.

"The expenditure under investigation relates to Accommodation Expenditure claimed under the Scheme. In accordance with the legislation and the procedures for investigation, no further information shall be published until the investigation has been concluded. Upon conclusion of the investigation, a report including details of the case made against the MP, evidence, findings and any sanctions will be published."

In response, Danczuck said: "I maintain that the existing rules are poorly worded and not fit for purpose when it comes to modern families like mine. Some of my Parliamentary colleagues have approached me in the last week to say they agree with me on this point and that they have interpreted the rules the same way.

"I'll be meeting with the chief executive of Ipsa about this and I will stress the need for the system to be more flexible to reflect the living arrangements of modern families. I am co-operating fully with the investigation and welcome the chance to get this matter cleared up."