A social worker accused of “colluding” with an abusive mother to silence allegations she beat her children was struck off today.

The Merton Council employee allegedly befriended the woman she was supposed to be monitoring and rubbished her estranged partner’s claims their children were in danger.

Doctors later found evidence the woman’s daughter had been physically abused, a hearing at the General Social Care Commission was told.

Celia-Gail Monique Smith, who worked for the council’s children in need team from July 2005 to August 2006, also failed to follow up warnings two children from another family were at risk of sexual abuse.

Some of her case files showed vulnerable young people on the child protection register, who should have been seen by the authority every four weeks, had not been visited in more than a year.

On Monday a hearing at the commission’s central London headquarters was told how Smith, who now lives in Jamaica and was not at the hearing, did not keep proper records on dozens of children on the child protection register and failed to follow procedures designed to keep them safe.

Karen Morgan, formerly Smith’s line manager, said the social worker had “colluded” with one abusive mother – with whom she would meet and have dinner – and warned other staff to “be careful” of claims by the woman’s partner as he was a liar.

Ms Morgan said: “She believed the mother without undertaking an investigation.”

The woman’s child was later found to have been beaten in the face and stomach.

In another case, a hospital called the department to say a mother brought to them following a drug overdose had warned her children were at risk of sexual abuse from their grandfather, who had abused her when she was younger.

The hearing was told when Smith was later challenged over a failure to launch an investigation into the claim, she said there was no need to do anything because the allegation had later been withdrawn.

On Wednesday the committee found Smith had committed gross negligence at the highest end of the misconduct scale, and removed her from the social care register.

Yvette Stanley, the council’s director for children, schools and families, said: “The protection, safety and wellbeing of children and families in Merton is of the highest priority for the council.

“As soon as concerns were raised about Ms Smith’s performance management action was taken.”