A police complaint has been made over the expense claims of Preston MP Mark Hendrick.
The complainant, who does not wish to be named but is from the Preston area, has written to the Metropolitan Police with "concerns" over Mr Hendrick after he paid back 6,850.52 of taxpayers' cash received on his second home allowance for a mortgage covering two properties.
The Met has responded to him in a letter stating that the "matter is under investigation".
The complainant told the Evening Post: "I was shocked at the revelations about MPs' expenses and it seemed to me that the vast majority of our MPs are unethical and self-serving.
"Having looked at Mr Hendrick as a local MP, it struck me that there was possibly a case for him to answer to the police and therefore wrote to the police and pointed out my concerns.
"I was particularly worried as to why he would have to pay back money."
He revealed that he has twice contacted the Metropolitan Police, including commissioner Sir Paul Stephenson.
In response, the Metropolitan Police sent him a letter featuring the reference "Operation Electra".
It reads: "I note your comments and observations, however, as the matter is under investigation I am unable to comment further regarding the progress of individual cases."
The Metropolitan Police refused to comment specifically on any investigation about Mr Hendrick's expenses.
Instead, a spokesman for the force said: "In June 2009, we confirmed that after consideration by the joint Metropolitan Police Service and Crown Prosecution Service assessment panel, the Metropolitan Police decided to launch an investigation into the alleged misuses of expenses by a small number of MPs and peers."
Mark Hendrick was not available for comment.
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