PORTLAND, Ore. – Police explained Thursday why they reopened a sexual assault investigation into Al Gore, saying an extra review was needed because detectives looking into the matter last year failed to notify high-ranking officials of their decision to drop the case.

A massage therapist to the stars has accused the former vice president of repeatedly groping and kissing her during a late-night, alcohol-fueled attack in a luxury hotel suite in October 2006. Gore adamantly denies the allegations.

Detectives investigated the claims in 2006 and 2009 but decided not to pursue the case amid a lack of cooperation and erratic behavior by the accuser. The story re-emerged last week after she told her story to the National Enquirer, and police this week said they would reopen the case.

Portland Police Chief Michael Reese said Thursday that “we have determined there were procedural issues with the 2009 investigation that merit reopening the case.”

Officers took the accuser’s statement but didn’t proceed further and didn’t clear that decision with higher-ups. In addition, prosecutors were not made aware of the 2009 investigation until recently.

Police would not say whether they would interrogate Gore or examine a pair of black pants the accuser wore on the night in question that she said became stained during the massage.

Gore has said through a spokeswoman that he “unequivocally and emphatically denies” the accusations and believes he will be fully exonerated once the investigation is complete.

“Further investigation into this matter will only benefit Mr. Gore,” said the spokeswoman, Kalee Kreider.

“We ask for the public’s patience as we let the facts of the investigation guide us and ensure the integrity of the investigation,” Reese said. “I have asked detectives to assign appropriate resources in the interest of conducting a complete investigation in an expedited manner.”

The investigation threatens to engulf Gore in a sex scandal once unthinkable for the Nobel prize winner who built up an image as a doting husband and family man who fell in love with his wife at the high school prom and lived happily ever after. The Gores’ squeaky clean public image always stood in sharp contrast to the troubled marriage of the Clintons during their time in the White House.

But Gore and his wife, Tipper, announced in June that they were breaking up, saying that they had grown apart after 40 years of marriage. Associates and family friends said there was no affair involved.

Not long after the split became public, Portland police announced that they had investigated Gore on sexual assault charges over the encounter with massage therapist Molly Hagerty in October 2006.

Police decided in 2006 not to pursue a case after her attorney told them she would file a civil complaint.

She came back to police in early 2009 and asked that they bring the case again, providing them a statement that spelled out in precise detail how Gore allegedly assaulted her.

She showed up at Gore’s ninth-floor executive suite late on the night of Oct. 24 while he was in town for a speech on global warming. “Call me Al,” she quoted Gore as saying as he gave her a big hug.

She said he was finishing up a beer when she entered the room, and told investigators it wasn’t long before an innocent massage turned into a series of unwanted sexual advances.

Hagerty said he dimmed the lights and asked her to massage the inside muscles of his thigh — a request she viewed as inappropriate. She refused and he allegedly put her hands on his genital area. Hagerty said Gore became angry when she pushed back.

Once the massage was complete and she began packing up her table, massage butters and other materials, Hagerty said Gore began to grope her.

“I squirmed to try and get out of his grasp, telling him to stop, don’t, several times, and I finally told him and said, ‘You’re being a crazed sex poodle,”‘ she told investigators.

She said she distracted Gore, and he stopped. Later, he tried to ply her with cognac and fondle her again, Hagerty alleges.

The Associated Press does not generally identify people who say they are victims of sex crimes, but Hagerty has made her identity public by giving an interview to the National Enquirer.