Charity scandal: Chief strategist for Save The Children, Brendan Cox, denied allegations against him but left the organisation in September

Another children’s charity was rocked last night after a senior executive at Save The Children resigned over allegations of ‘inappropriate behaviour’.

Chief strategist Brendan Cox denied allegations against him but left in September. The charity’s £160,000-a-year chief executive Justin Forsyth has also resigned for unconnected reasons.

Both were senior advisers to former Prime Minister Gordon Brown. Mr Cox’s wife, Jo, is a Labour MP and former aide to Mr Brown’s wife Sarah. Mrs Cox also runs the Labour Women’s Network where she is ‘equalities and discrimination’ adviser.

Mr Cox, Save The Children’s director of policy and advocacy, left in September after complaints against him by women members of staff. A well-placed source said Mr Cox strenuously denied any wrongdoing but agreed to leave his post.

The source denied Mr Forsyth had quit due to the dispute involving Mr Cox – but said it had ‘hurt him’. The charity investigated claims that Mr Forsyth failed to act firmly against Mr Cox but found no evidence to support the charge, the source added.

An insider said: ‘Some people were unhappy there was no proper internal investigation into the allegations. Brendan packed his bags and left suddenly.’

One individual who has worked with Save The Children said: ‘Several of the women complained about inappropriate behaviour by Brendan. When the charity did nothing about it they threatened to make a huge fuss. Shortly afterwards it was announced that Brendan was leaving. Then we heard Justin was going as well.’

In a resignation letter to staff, Mr Forsyth said he was leaving after having discussed the matter with charity chairman, Sir Alan Parker, head of public relations giant Brunswick.

Mr Forsyth said he did not yet have a new job to go to, adding: ‘I hope to take a short breather before undertaking the next step of my career.

‘I have a few exciting irons in the fire that are too early to talk about.’

The arrival of ambitious Mr Forsyth and Mr Cox, both fervent Labour supporters, at Save The Children after Mr Brown lost the 2010 Election led to a major change in the charity.

Second resignation: The charity’s £160,000-a-year chief executive Justin Forsyth has also resigned for unconnected reasons

Mr Forsyth was branded one of a new breed of charity ‘fat cats’ with a £160,000 salary, expenses of £3,000 a year and £11,000 for his pension pot. Backed by Mr Cox, Mr Forsyth ordered a highly emotive multi-million pound TV advertising blitz. The ‘It Shouldn’t Happen Here’ campaign claimed 1.6 million British children were growing up in ‘severe poverty’. Tory MPs said it was a ‘crude political campaign against Government cuts.’

Asked about the allegations from female staff of inappropriate behaviour by him, Mr Cox said last night: ‘These rumours are untrue.’

When this newspaper asked the charity last month about Mr Cox’s departure, a spokeswoman said: ‘We never comment in any circumstances on individual members of staff past or present.’