Mohamed Kendeh, who sexually assaulted 11 women, at first successfully claimed deporting him to Sierra Leone destroyed his right to a family life here.
But he went on to be jailed again for robbery in 2009, prompting renewed efforts to deport him. The 25-year-old was finally sent back to Freetown on Sunday, the Home Office said.
It comes as Home Secretary Theresa May’s attempts to deport radical cleric Abu Qatada, once described by a judge as Osama bin Laden’s right-hand man in Europe, are being frustrated by human rights laws.
Gabrielle Brown, one of illegal immigrant Kendeh’s victims, said: “It’s fantastic news.”
Ms Browne, who was training for the London Marathon on a towpath when she was sexually attacked by Kendeh in 2003, welcomed the move, saying he should never have been allowed to stay.
Ms Browne, 46, who has waived her right to anonymity, said: “I’m very pleased he has been deported. This should have happened in 2007 when he was, in my view, wrongly allowed to remain in the UK.”
It emerged after his arrest that he had recently been from a young offenders institution after sex assaults on four women when he was 15.
Immigration Minister Damian Green said: “Kendeh committed appalling crimes but made every attempt through the courts to thwart his removal and further prolong the suffering of his victims.
“I am pleased he has now been successfully returned to his home country.”
Kendeh claimed his right to a family life under Article 8 of the European Convention on Human Rights, which is enshrined in UK law under the Human Rights Act.
Mr Green went on: “For too long Article 8 has been used to place the family rights of foreign criminals and immigration offenders above the rights of the British public.
“This is why we will change the immigration rules to reinforce the public interest in seeing foreign criminals and those who have breached our immigration laws removed from this country.”