An attempt to smuggle drugs concealed in tennis balls into a prison has ended in the culprit being locked up for 10 months.

Adrian Marshall, 20, was caught before the balls, filled with strong skunk cannabis, could be tossed over the wall of Swaleside jail at Eastchurch.

The 20-year-old and Jordon Shekoni, 19, were spotted by plain clothes officers patrolling the perimeter.

Marshall was convicted of conspiracy to smuggle the drug and mobile phones into prison.

Shekoni, a semi-professional footballer, was convicted of the mobile phones offence and cleared of the drugs charge.

He was sentenced to two months youth custody suspended for a year, with 40 hours unpaid work.

Shekoni, who plays for Raynes Park FC, will also be restricted by a curfew from 9pm to 6am for three months.

Marshall and Shekoni wore dark clothing as they prowled around the prison walls in December 2010, Maidstone Crown Court heard.

When the officers shone torches at them they changed direction and walked away.

A police dog recovered a discarded carrier bag. Inside were two tennis balls which had been cut in half, stuffed with cannabis and re-sealed with tape.

"They would have been lobbed over the prison walls and picked up by prisoners at a later date," said prosecutor Meyrick Williams.

There were also eight mobile phones in four packages.

Marshall, of Brixton, South West London, and Shekoni, of Tooting, South West London, denied conspiracy to convey cannabis into prison.

Marshall also denied conspiracy to convey mobile phones into prison, while Shekoni admitted that offence.

Paul Brooks, for Shekoni, said the teenager accepted he had been recruited to deliver the mobile phones, but was unaware there were drugs in the bag.

He was taking a BTEC course but hoped to become a professional footballer.

Tom Dunn, for Marshall, said his client was "not criminal to the core".

Judge Philip St John-Stevens said taking such items into prison was a serious matter. Use of tennis balls, he added, was a common method to get drugs to prisoners.