MP Mark Menzies will stand down at the next election and has quit the Conservative Party, after it found he had shown a “pattern of behaviour” falling below the standards for MPs.
The Fylde MP had been accused of using party money to pay off “bad people”.
The party said it “cannot conclude” whether party funds had been misused because the money came from a body that sits outside of its remit.
Mr Menzies has previously strongly denied the allegations.
The MP was suspended from the Conservative Party earlier this week after claims emerged in the Times that he had called a party activist in the early hours of the morning last December to ask for £5,000.
He said he needed the money to pay “bad people” who had locked him in a flat, reportedly saying it was a matter of “life and death”,
Mr Menzies was also accused of using £14,000 in party funds to pay for medical bills.
In a statement on Sunday, Mr Menzies said he was standing down “due to the pressures on myself and my elderly mother”.
He continued: “This has been a very difficult week for me and I request that my family’s privacy is respected.”
The Conservative Party said it had concluded an internal investigation, which found the money sent to Mr Menzies “was signed off by the two signatories of Fylde Westminster group”.
The party said that group was “outside of the remit” of both the Conservative Party and the local Fylde Conservative Association, adding: “Therefore we cannot conclude that there has been a misuse of Conservative Party funds.”
Its investigation also found Mr Menzies may have breached the Nolan principles, which are supposed to guide public office-holders. They are selflessness, integrity, objectivity, accountability, openness, honesty and leadership.
Its statement continued: “This is due to the nature of the allegations made, but also the repetitive nature of these separate allegations. These will be reviewed by the Conservative Party’s member governance team.”
Earlier this week, Lancashire Police said it was aware of the reports about Mr Menzies but had not received a formal complaint.
A statement from the force continued: “We will make contact with those impacted in due course to see whether they wish to make a complaint.”
On Sunday, the Tory Party said it would “share any information with the police if they believe it would be helpful to any investigation they decide to undertake”.
The party was first made aware of allegations regarding Mr Menzies in January, and Labour has criticised how the matter has been handled.
After announcing the results of its investigation, the Tory Party said “suggestions the party has not been seriously examining this matter are demonstrably false”.
It also said it would retrain individuals across the party on how to manage “accounts which fall outside of the remit of the Conservative Party” and set up a whistleblowing helpline.
Mr Menzies will sit as an independent MP until the next election, which means there will not be a by-election in the constituency.