IMMIGRATION officials are checking the backgrounds of 15 West Indians arrested when police on Teesside seized their biggest haul of crack cocaine.

About 24 officers were involved in the recovery of 250 "rocks" of the drug in raids on two addresses in the same town centre neighbourhood of Middlesbrough, this week.

Nineteen people were arrested, 15 men and four women, who are being questioned at police stations across Teesside.

Cleveland Police also recovered a cache of weapons. A force spokesman said: "All the males are of West Indian origin and many come from other parts of the country.

"Immigration is involved in checks on these people. Inquiries are also being made with other police forces in the UK.''

Quantities of the banned drug were found concealed in the walls of a house in Walpole Street, packed with cloves of garlic to throw police sniffer dogs off the scent if the premises were raided. As police went in through the front door bags of the suspected drug were thrown from a bedroom window.

Fifty rocks of crack cocaine were recovered from a house in nearby Princes Road, as well as what a force spokesman described as "substantial" sums of cash.

The seized drugs have been sent to police forensic laboratories at Wetherby for analysis.