Media playback is unsupported on your device Media caption Simon Wood killed himself shortly before he was due in court in August 2013, as Angus Crawford reports

The BBC has uncovered new evidence indicating British Airways was told of concerns about a pilot's behaviour.

First Officer Simon Wood allegedly sexually assaulted at least 50 children in Kenya and Uganda between 2001 and 2013.

It is believed that BA staff were told of concerns about Wood's behaviour twice in that time.

The airline says it's "shocked and horrified" by the allegations and that its "sympathies are with the victims."

A number of those victims are now suing the airline for compensation.

BA says it will "robustly" defend itself against the action.

Anonymous tip off

Wood, 54, from Potters Bar, Hertfordshire, flew BA routes to Kenya and Uganda for more than a decade.

There he volunteered at several charities including an AIDS orphanage.

In July 2013, Wood was arrested by police after an anonymous tip-off. He was charged with indecent assault and possessing indecent images.

In August that same year, shortly before he was due to appear in court, Wood killed himself.

It later emerged that he was first arrested over an indecent assault allegation in the UK in 2001.

Prosecutors ruled there was insufficient evidence to charge him.

Image copyright Jonathan Goldberg Image caption In 2010, Wood won BA's Corporate Responsibility Award "for dedicating hours of his time" to charity work

Dismissed from charity

BBC News has learned that in July 2004 he was dismissed from the British board of Nairobi-based charity Nyumbani, because he had been found taking pictures at the charity of naked children at bath time.

Mike Johnson, another BA pilot who was also on the board, said: "Copies of the photographs were obtained and presented to the board".

Wood was removed from the board and told not to visit Nyumbani again.

Mike Johnson informed two senior managers at BA about what had happened.

"We had asked Simon Wood to leave the Nyumbani board and we had suggested to the hospice in Kenya that he shouldn't visit".

He heard nothing more from the managers and left BA the same year.

"Whether BA should have been looking at all of his activities and supervising those activities is a very difficult question," he added.

'Parents are complaining'

The mother of one victim told the BBC that she sent an email to another member of BA staff four years later, in 2008.

The mother claims that her daughter, who was then just 11, was raped by Wood at his hotel.

Other girls also complained about his behaviour.

Sarah's email was sent to another BA pilot involved in charity work in Kenya.

BBC News has seen a copy of the message, which reads: "Parents are complaining...that Mr Simon is using their daughters to satisfy his sexual desires".

"...whenever Mr Simon is in Nairobi he takes them to the hotel where he stays".

It appears that no action was taken by BA against Wood following the incidents in 2004 and 2008.

Image copyright PA Image caption BA said it was "shocked and horrified" to hear the allegations against Wood

'Now I hate him'

I met two of Wood's alleged victims. One used to live at a charity, where he was a frequent visitor.

She said: "At first he was good, he used to give us gifts and take us on outings."

He slept in a room next door, and would come in to her dormitory and abuse her, she was five years old.

"Now I hate him, now I don't feel like he was a good person," she said.

The second lived at another orphanage.

Wood liked to come early in the morning, line the girls up, then wash them one by one in a locked room.

"When he came that was the worst day of my life", she said.

"We had no choice - I felt very bad".

Millions for charity

BA raises millions of pounds for charities around the world every year and staff are encouraged to volunteer.

In 2007, Wood was a winner in the BA Community Volunteering Awards.

Again, in 2010 he won BA's Corporate Responsibility Award "for dedicating hours of his time" to charity work in Kenya.

Now BA is being sued by the London law firm Leigh Day on behalf of 35 of Wood's victims.

Nichola Marshall, head of the firm's foreign abuse team, said: "They have a duty to ensure that the staff that are carrying out the charitable activities... are not abusing the children."

BA said it cannot comment while legal proceedings continue, but has released a statement.

"We were shocked and horrified to hear the allegations against Simon Wood and our sympathies are with the victims.

"These allegations have been raised in the context of litigation which will be robustly defended."