Image caption Al Gore announced he was separating from his wife last month

Police in the US are reopening an investigation into allegations that former Vice-President Al Gore made unwanted sexual advances to a woman at a hotel in 2006.

Police in Portland, Oregon, had earlier said they considered the case closed because there was no evidence.

A spokeswoman for Mr Gore said he "unequivocally" denied the allegations.

She said Mr Gore welcomed the investigation, which would "only benefit Mr Gore".

A spokeswoman for the police department said it would not make any comments on the case.

Cancelled appointments

The massage therapist alleges that Mr Gore made unwanted sexual advances during a massage appointment on 24 October 2006 at the Hotel Lucia.

Mr Gore was in Portland to deliver a speech on climate change.

Last week, Portland police said the woman's lawyer had come to them with the allegations in 2006, but that she had then cancelled appointments with detectives and said she did not want the investigation to proceed.

The case was reopened in January 2009, when detectives interviewed the woman, but they determined there was insufficient evidence to support her claims.

She said Mr Gore, 62, who was awarded the Nobel peace prize in 2007, had become enraged when she refused his advances.

After the alleged incident, the woman said she was dissuaded from contacting the police by friends of hers.

One friend "was basically asking me to just suck it up, otherwise the world's going to be destroyed from global warming", she said.