Republican congressman Patrick Meehan has said he will resign immediately over sexual harassment allegations.

The Pennsylvania representative was to be investigated by the ethics committee over accusations that he sexually harassed a female ex-staffer and used taxpayers' money to settle with her.

Mr Meehan, 62, also said he planned to pay back the full $39,000 (£28,000) of the settlement money.

Earlier this year, he stated that he would not seek re-election.

Mr Meehan maintained in a press release that he had not acted unethically.

"While I do believe I would be exonerated of any wrongdoing, I also did not want to put my staff through the rigors of an Ethics Committee investigation and believed it was best for them to have a head start on new employment rather than being caught up in an inquiry," Mr Meehan said.

"Since I have chosen to resign, the inquiry will not become a burden to taxpayers and committee staff."

The four-term congressman was under pressure to resign since allegations emerged in January that he had harassed an aide three decades his junior.

The aide had said Mr Meehan, who is married with three children, became hostile when she did not return his romantic interest.

Mr Meehan admitted he saw the younger woman as his "soul mate".

The House Ethics Committee had no comment on Mr Meehan's resignation.

Mr Meehan added that he will pay back the US Treasury for the severance payment made from his account because he "did not want to leave with any question of violating the trust of taxpayers".

Before his resignation, Mr Meehan was one of two Republicans to stand with House Democrats in support of a resolution to investigate Speaker Paul Ryan's motivation for sacking the House chaplain, Fr. Patrick Conroy.