Charges alleging Kevin Spacey groped an 18-year-old man in 2016 have been dropped by prosecutors in Massachusetts.

The House of Cards star's accuser refused to testify at a court hearing about a missing mobile phone of his that defence lawyers claimed could prove the actor's innocence.

Spacey's accuser invoked his Fifth Amendment right, which protects people in the US from being forced to incriminate themselves.

He did so after being asked if he knew that destruction of evidence was a felony under Massachusetts law.

A statement from prosecuting lawyer Michael O'Keefe confirmed the 'nolle prosequi', or formal notice of the case being dropped.

The accuser, who is the son of former TV news presenter Heather Unruh, claimed Spacey had gotten him drunk in a bar before sexually assaulting him.

Spacey's lawyers claimed text messages between the pair would prove no crime had taken place and demanded the accuser hand over his mobile phone - which he refused to do.

O'Keefe's office then filed the nolle prosequi after meeting with the accuser, his lawyer and family members, reports the Boston Globe.

However, the alleged 2016 groping is not the only accusation of sexual misconduct Spacey has faced.

His career was derailed in 2017 after fellow actor Anthony Rapp made public allegations that Spacey made a sexual advance toward him at a party in 1986, when Rapp was aged 14.

As of December, 2018, more than 30 different people have made allegations against Spacey.

Newshub.