PORTLAND — Federal prosecutors will recommend that prominent developer and entrepreneur Michael Liberty serve six months in jail or under home arrest for illegally masking $22,500 donations to a presidential campaign.

Liberty, 56, earlier this year pleaded guilty to making $22,500 in illegal campaign contributions, which court documents indicate benefited Republican presidential candidate Mitt Romney’s 2012 campaign.

In a sentencing memo filed Monday, federal prosecutors wrote that Liberty’s sentence and possible minimum fine of $67,500 should serve as an example of the crime they said is typically hard to prove.

“[W]hile the defendant himself is unlikely to orchestrate a conduit-contribution scheme in the future, the sentence should promote general deterrence so other sophisticated political fundraisers are dissuaded from engaging in such conduct,” the memo states. “In the government’s view, a sentence at the bottom of the guideline range would both promote respect for the law and further the need for deterrence.”

Liberty made nine donations in the names of “employees, family members and associates,” totaling $22,500 in contributions between May 13, 2011, and June 1, 2011, according to the complaint.

Prosecutors said convictions in such cases “are relatively rare” because they require detection of the concealed donations and proof of an intent to violate the Federal Election Campaign Act.

Liberty is scheduled to go before a judge June 28 for sentencing.

Separately, the entrepreneur once dubbed “Donald Trump with a Maine accent” is accused of lying to securities regulators, telling them he was broke, in order to reduce a $6 million fine on charges of fraud. Liberty’s attorneys and financial regulators are scheduled to have a settlement conference June 5 in that case, according to court records.

Early in his career, Liberty was a developer of the 91-unit Chandler’s Wharf condo project and two office towers at 100 Middle St. in Portland. He also was an owner of the Oxford Plains Speedway.

His later career was defined by founding the mobile payment startup Mozido, based in Austin, Texas, and his patents on mobile wallet technology.