A cleaner who threw what appeared to be a smoking bomb at his boss has been jailed.

James Hasler, 34, had shouted “I’ve had enough. I quit” before lighting a fuse on the device, Ipswich Crown Court heard yesterday.

The terrified manager who was the target of the prank at the Kingfisher Leisure Centre in Sudbury, John Scarff, needed six weeks of counselling to recover from the ordeal.

Hasler, of Woodhall Road, Sudbury, had returned to Mr Scarff’s office moments later to say that it had been meant as a joke. Hasler was immediately suspended from his job.

The whole incident had been caught on CCTV and the recording was shown to the court.

Judge John Devaux jailed Hasler for 14 months for placing a hoax homb. Hasler had also pleaded guilty to production and possession of cannabis.

Edward Renvoize, prosecuting, said Mr Scarff, who had experience of munitions from his RAF service, had been badly shocked when Hasler burst into his office on October 18 and threw what appeared to be dynamite.

Mr Scarff had managed to kick away the smouldering device, consisting of three red tubes taped together with a fuse, and it had gone out.

Police arrested Hasler early the following day at his home where a search uncovered chemicals used in the production of fireworks.

Also found were three cannabis plants and a small quantity of cannabis which the court heard Hasler had smoked on the daily basis for the past 13 years.

Hasler had told police: “The intention was a joke. I did not intend to cause any fear.”

Defending, Jonathan Seely said Hasler, who had expressed considerable remorse, had not been pursuing any form of vendetta or dispute against Mr Scarff.

Mr Seeley told the court: “Perhaps astoundingly at this time the defendant was in the process of applying for a pay rise and which Mr Scarff was helping him with.”

Hasler’s sense of humour was, at times, “monstrously bad” said Mr Seely.

Giving evidence about his son, Stephen Hasler said: “He does like playing jokes and perhaps doesn’t realise that some of them are not funny.”

Sentencing him, Judge Devaux told Hasler: “Happily the fact is these cases are unusual.”

Judge Devaux granted a restraining order banning Hasler from contacting Mr Scraff for the next three years.

Tracey Loynds, chief executive of South Suffolk Leisure which manages the Kingfisher centre on behalf of Babergh District Council, told the EADT: “The incident was managed quickly and efficiently by our team and by Suffolk Constabulary. We are now keen to put this event behind us and move on.”