An amended return for the 2011 campaign has been posted to the Elections Canada website that shows Penashue's campaign accepted 28 separate illegal contributions.
The Labrador MP has paid the federal Receiver General $47,660 in four separate instalments, meaning the donations were non-monetary contributions that can't be refunded to the donors.
Penashue quit the cabinet of Prime Minister Stephen Harper this week and says he'll run for the Conservatives in a coming byelection in an effort to clear the air.
While Penashue only stepped down this week, the Elections Canada records show he paid back $26,850 last November.
He won his seat by just 79 votes in an upset over Liberal incumbent Todd Russell in 2011. An initial Elections Canada review subsequently showed Penashue spent $4,000 over his limit of just under $84,500.
He also appeared to have accepted thousands of dollars in free flights across his expansive, remote riding.
Among the refunded donations is an entry for $18,710 for Provincial Airlines Ltd.
Penashue also refunded $5,500 from a St. John's construction company that had listed the donations under five individual employees.
All the other ineligible donations were for $1,100 each or less.
Penashue has blamed the campaign problems on an "inexperienced volunteer" in his organization — his official agent, Reginald Bowers.
Bowers was subsequently appointed by the federal government to the Canada-Newfoundland and Labrador Offshore Petroleum Board, which regulates the oil sector, but quit the post soon after Penashue announced his resignation late Thursday.
"He's personally resigned and turned the decision over his future to the people of Labrador and he's going to give them an opportunity to consider his entire record," Conservative MP Pierre Poilievre told CBC.
Penashue is not the only Conservative MP currently suffering under a campaign spending investigation.
Peterborough, Ont., MP Dean Del Mastro, the parliamentary secretary to the prime minister, is being investigated for his 2008 campaign return, with Elections Canada court documents suggesting he overspent his legal limit by $17,000 and then tried to cover it up.
The allegations have not been proven in court and no charges have been laid.
The prime minister has up to six months to call a byelection in Labrador.
Yvonne Jones, a Liberal member of the Newfoundland and Labrador legislature, says she wants to the Liberals federally in the riding.
Jones, a former provincial Liberal leader, says she intends to seek the federal Grit nomination because she believes Labrador deserves better representation in the House of Commons.
Jones represents the Labrador riding of Cartwright-L'anse au Clair in the provincial legislature. She was first elected in 1996 and later became a cabinet minister.