Former US congressman Anthony Weiner has been sentenced to 21 months in prison for sending sexually explicit messages to a 15-year-old girl.

The 53-year-old for New York politician had previously pleaded guilty to one count of transferring obscene material to a minor.

Prosecutors had argued for a sentence of between 21 and 27 months, while defence attorney's for Weiner had argued against a prison sentence.

His lawyers had argued the disgraced politician acted out of the "depths of an uncontrolled sickness" and was now being treated.

Weiner himself had admitted: "I have a sickness, but I do not have an excuse."

As well as his prison term, Weiner was also fined $10,000 (€8,400) and must enrol in a sex-offender treatment programme.

He had faced up to 10 years in prison.

Acting Manhattan US Attorney Joon H Kim earlier this year said: "Weiner's conduct was not only reprehensible, but a federal crime."

Weiner was married to Huma Abedin, one of Hillary Clinton's senior aide. Ms Abedin filed for divorce earlier this year.

With only days to go until last year's presidential election, the investigation into Mr Weiner's conduct offered an unexpected twist in the dramatic race.

The FBI temporarily reopened its probe of Hillary Clinton's use of a private email server after related emails were discovered on a computer used by both Mr Weiner and Ms Abedin.

It was announced only two days before polls opened that no new evidence related to the closed Clinton investigation had been found.

Weiner's once-promising political career culminated in a high-profile bid for New York mayor in 2013, but his campaign ended in failure in the wake of sexting scandals.

He had previously resigned from Congress in 2011 after a sexually explicit photograph was posted via his Twitter account.

Additional reporting by IRN