Two teenage boys with autism were found malnourished and naked in a Brisbane home where police found a man dead.

Police had been responding to the discovery of a 49-year-old man’s body in the front yard of a Stafford property on Wednesday morning when they found the teenagers, aged 17 and 19, after hearing sounds from a locked bedroom.

The 49-year-old man, whose death is not being treated as suspicious, was understood to be the father of the pair.

Neighbours said the boys had been living in squalid conditions.

Photos and footage obtained by the ABC dating back to October 2018 show the teenagers wearing only nappies in a room with smeared excrement on the walls and the floor.

A neighbour said she contacted the Department of Child Safety in February but was told there was nothing they could do.

She said her family had witnessed the man’s “disgusting” mistreatment of the boys over the past 18 months and recalled seeing the teenagers being locked outside “in nothing but a nappy”.

“I rang [the department] because to me, I couldn’t believe how hot it was, that you would leave a child outside,” she told the ABC.

“[The department] basically said because they technically have shade, and they technically are in an enclosed yard, there’s nothing that they can do, which doesn’t sit well with me being a mum.

“They didn’t even ask me for the address.”

Another neighbour said it was “extremely difficult to see it, hear it, know it all the time and not being able to do anything about it and to try and get things done about it … but just not being heard by people who could change it.”

A Queensland Ambulance spokesman said the teenagers were being treated at Prince Charles hospital.

Queensland’s minister for child safety Di Farmer said her “thoughts are with these two young men who are getting the support and care they need”.

The Department of Child Safety, Youth and Women said it could not confirm whether they were investigating the situation.

“The strict provisions of [the Child Protection Act] make it illegal to disclose publicly whether an individual or family is known or not known to the department,” it said.