A shocked mother was disgusted to discover a peeping Tom spying on her and her baby in a swimming pool changing cubicle at Dunstable Leisure Centre.

She had taken off her swimming costume, wrapped herself in a towel and undressed her baby daughter when she caught sight of the pervert, watching them from under the cubicle wall.

The 35-year-old mum shouted angrily at him and rushed out to confront him, with the seven-month-old baby girl in her arms. But he shrugged off her furious complaints and left the changing area.

Now she and a friend, who was in another cubicle with her own seven-month-old baby son, are angry about what they see as security lapses.

And they point out that the incident happened at a time when a number of children were changing for swimming lessons, at about 4pm on Wednesday. The mums had just finished a happy swimming session with their babies.

They say the pervert, who appeared to be drunk, could walk straight into the area, as a security barrier at the entrance to the changing rooms was not in use at the time.

Staff usually operate the barrier to control entry to the changing area, and centre users can open the barrier from inside to exit the area.

The barrier was not in use because it was a peak period when many children were arriving with their parents, including mums with pushchairs, for swimming lessons.

The Houghton Regis mum targeted by the pervert said: "The security up there wasn't very good and there were a lot of kids about up there. I don't know if it was me he was trying to look at or my little daughter. You just don't know."

She had seen the grey-haired man loitering in the changing area. He appeared to be in his 50s, of medium build, about 6ft tall and was smartly dressed in a blue shirt and pale blue jeans.

The mum was uneasy, but assumed he was waiting for someone to get changed.

"I could tell by the way he was walking that he was drunk," she said. "It was quite obvious he had had a few."

In the cubicle, she took off her swimming costume, wrapped a towel around her and started to attend to her baby daughter.

The mum said: "I'd got her undressed and I was drying her. I just noticed a shadow on the floor and I thought somebody had gone in there (the cubicle next door) to get changed. I didn't think anything of it, I carried on."

Then she spotted the peeping Tom, just as he was moving away from under the cubicle wall.

She shouted at him, calling him a "dirty pervert" and confronted him outside. "He just said, 'it's all right', and carried on walking, and I said, 'it's not all right'," she said.

Another woman, who was fully dressed, followed him out of the changing area and said she would report the incident.

The mum went back to dress her baby after being comforted by her friend.

She said: "It was a horrible thing to happen. You just don't expect that."

Her friend, a 28-year-old Houghton Regis mum, said: "Obviously, she is very upset, we both are. It could have happened to anybody in there.

"There were children in there without adult supervision, getting changed for their swimming session."

The irate mums reported the incident to the management and later to the police.

Nick Parkin, the centre's contract manager, said a full investigation was being carried out in conjunction with South Beds District Council and the police.

The police would be invited to review the centre's procedures to see if they could be improved in any way.

He was unable to comment further until the investigation into the allegations had been carried out.

Anyone who saw the peeping Tom, or who has any information about him, is asked to contact Dunstable police on 01582 471212.