US President Donald Trump on Friday commuted the sentence of disgraced former Republican lawmaker George Santos, who was convicted of committing wire fraud and identity theft to splurge on lavish vacations and Botox injections with funds stolen from campaign donors.

"George has been in solitary confinement for long stretches of time and, by all accounts, has been horribly mistreated," Trump wrote in a lengthy post to his Truth Social site Friday.

"And at least Santos had the Courage, Conviction and Intelligence to ALWAYS VOTE REPUBLICAN," he added.

"Therefore, I just signed a Commutation, releasing George Santos from prison, IMMEDIATELY."

A presidential commutation is different from a pardon in that the original conviction stands – but the sentence passed is reduced.

The 37-year-old ex-representative from New York state reported to prison in July, after being sentenced to seven years and three months in April for stealing campaign donors' identities and using their credit cards, among other charges.

A congressional ethics committee investigation found he used the stolen funds for Botox treatments and the OnlyFans pornography website, as well as luxury Italian goods and vacations to the Hamptons and Las Vegas.

Santos's bizarre biographical fabrications included claiming to have worked for Goldman Sachs, being Jewish and having been a college volleyball star.

He was expelled from the House of Representatives in 2023, one year after he was elected to office, becoming only the third person to be ejected as a US lawmaker since the Civil War, a rebuke previously reserved for traitors and convicted criminals. (AFP)