They plan to hire a private investigator to probe further into the case.

Speaking to the Sunday Tribune last week, Winnie Brady's sisters Dolores Flynn and Bernie Shevlin voiced serious concerns about the circumstances surrounding the disappearance of the 59year-old Dublin woman.

"My sister and I believe that something sinister happened to Winnie, " said Flynn.

"It was not an accident, whatever happened to her."

Brady, from Kilbarrack in north Dublin, was last seen on 6 September at around 1pm. She was on her third trip to Medjugorje with a party of around seven friends.

Brady had bad arthritis in her legs, and on the day she disappeared was unable to accompany her group to a prayer meeting because of the pain in her knee.

"We only found out recently that she had a big row. It was a serious argument. We think something bad happened to her."

The fact that no trace of Brady was ever found has convinced her sisters that there is more to this disappearance than an accident.

"They searched for four days, there was a helicopter and dogs and a big search team, " said Flynn. "Winnie had arthritis. She wasn't ever going to be able to go very far.

Her passport, cigarettes, money and tablets were all left in her room. If she had fallen, or hurt herself somewhere, they would have found her."

In an effort to get answers, friends and neighbours in the inner city have organised a raffle to raise money for a private detective.

"We've got Euro10,000 in a bank account at the moment, " said Flynn. "We need around Euro50,000 to pay a private detective to go over there. We don't care how long it takes, we're going to fight for her.

"Our two other sisters have died, but we were able to grieve for them. We can go to their graves. With Winnie, there's no closure. We phone each other up in the middle of the night when we can't sleep for thinking about it. The longer it's getting, the worse it's getting. We just want answers. She has to be somewhere, whether she's dead or alive, she has to be somewhere."