A South Australian man became inspired to try and make his own weapons — including explosive devices and a deadly toxin — after watching a television show, a court has heard.

Key points: Benjamin John Whitehouse pleaded guilty to possessing a sawn-off air rifle

Benjamin John Whitehouse pleaded guilty to possessing a sawn-off air rifle His application for bail was adjourned for two weeks

His application for bail was adjourned for two weeks Prosecutors fear he is a risk to the community

Benjamin John Whitehouse today applied for bail in the Adelaide Magistrates Court, before his request was adjourned for two weeks.

The 42-year-old is charged with two counts of taking steps to manufacture an explosive device and five counts of possessing a prohibited weapon after police raided his home at One Tree Hill last December.

He pleaded guilty today to one count of possessing a sawn-off air rifle but is yet to plea to the remaining counts.

Prosecutors opposed his application for bail, saying they held concerns that Mr Whitehouse would be a "serious risk to the community".

The court was told police went to Mr Whitehouse's residence after a report of a domestic violence incident before finding a "sparkler bomb" and two 3D printers at the premises.

"As a result, the Bomb Response Unit was called to attend," the prosecutor said.

"That Bomb Response Unit X-rayed the sparkler bomb and at that point, determined it was a viable improvised explosive device."

"It was placed in a glass container vessel and that device has subsequently been analysed."

Police found document, 'build your own machine gun'

He said officers also allegedly found a document entitled 'build your own machine gun', and another with information about Ricin — a "toxin that can be extracted from castor beans".

The court was told two packets of castor beans were found at the premises.

"Additionally, police located a number of sling shots and rifle crossbows," he said.

Prosecutors told Magistrate Elizabeth Shepperd that police also allegedly found other weapons — including a double-edge throwing knife, sling shots and a black arrow — in the back of a car.

He said police conducted another search and found a second "explosive device" — a "small plastic pipe about 20 centimetres long with a diameter of two centimetres".

"[His former partner] states that in 2018, she had a conversation with the defendant after he had watched a television series. This television series, in essence, fostered an interest in the defendant in explosives," he said.

"It's alleged the defendant told [his former partner] that in order not to be traced you need to buy ordinary materials from a hardware store that can be modified into a bomb."

He said Mr Whitehouse showed his ex-partner the paperwork about how to make Ricin out of castor beans.

Defence lawyers say the bomb was 'not sophisticated'

But counsel for Mr Whitehouse asked Magistrate Shepperd to have a look at the police images of the sparkler bomb, saying it was "not a sophisticated bomb".

"It does seem quite sinister to call something a sparkler bomb — they're sparklers wrapped in a roll of toilet paper, covered in duct tape," she said.

Ms Shepperd interrupted the bail application and asked if it could be adjourned because of the high number of cases before her today.

But she said there was "absolutely no way" she would release him on bail but would consider home detention.

The bail application will be back before the court in two weeks.