South Wales Fire Service has suspended its support for a charity after complaints about its religious connections.
Children from poorer countries are sent the shoebox gifts
Operation Christmas Child, which was founded in north Wales in 1991, sends boxes of presents to poor children in 14 countries across the world.
The fire service usually offers its depots as collection points - an offer it has now withdrawn after claims the charity was
sending evangelising literature in the gift boxes.
The organisers of Operation Christmas Child, have denied putting evangelising literature in the boxes, but say they do offer Bible stories separately to children in countries where it is felt appropriate.
A spokeswoman for the fire service said: "We have suspended our involvement for this year while we carry out a review."
She said that the fire stations would not be acting as collection points for the shoeboxes while the complaints, which were made by the National Secular Society, were investigated.
The society, which is a pressure group for athiests and other non-believers, said it was angry that donors of the shoeboxes were not told about Operation Christmas Child's connections with evangelism.
Norman Hillier, the brigade's director of corporate services said that the fire service had only got involved with the charity after seeing it as the "harmless collection of toys and gifts for needy children overseas at no cost to the service".
However he said that following the complaints they were using standard procedure to review their participation.
But Samaritan's Purse UK, which runs Operation Christmas Child, has defended the project and said that no religious literature was placed in any of the 1.3 million shoeboxes that were sent last year.
"We go to strenuous lengths to ensure this [sending out evangelising literature in the gift boxes] does not happen," said David Vardy, the executive director of the charity, which has links to a US-based group whose president is Franklin Graham, son of the evangelist Billy Graham.
"Our leaflets which we give to anyone who wants to send a shoebox, contain specific guidelines on what to put into a box and what not to put into a box.
"Very clearly we tell people not to put in any literature that is of a political, religious or racial nature.
More than a million shoebox gifts are sent every year
"Furthermore we actively check every box we receive and remove any such literature which we find."
But he admitted that a booklet of Bible stories was sometimes sent out separately to the shoeboxes where it was deemed appropriate.
"Where it is appropriate, and in approximately half of the distributions it is not, a booklet of Bible stories, in the language of the country is offered separately from the shoebox," said Mr Vardy.
"There is no obligation whatsoever on any child to receive a booklet.
"The shoeboxes are given without discrimination and unconditionally to children regardless of their nationality, political background or religious beliefs."
He also added that he was 'disappointed' that South Wales Fire Service would not be taking part in the scheme but said that alternative collection points would be made available to people wishing to donate.