NATURE (7.30pm BBC2) this week uncovers the 'Bear Necessities' of an illegal trade. In the best tradition of screen cops, Canadian government agents are going undercover to stop the unlawful trafficking of a commodity twenty times more expensive than heroin - bear gall. In the Far East, this organ is prized for its medicinal properties; five specks sell for pounds 300 in South Korea. Since the black bear is rapidly dying out in the Orient, dealers are turning to North America for their supplies of gall. But Canadian trappers are only permitted to kill two black bears a year, and demand far exceeds (legal) supply. Andrew Serraillier's film employs techniques a Roger Cook investigation would be proud of - all blotted-out faces and hidden cameras and microphones - and tracks down characters straight out of a Davy Crockett movie. One trapper rails against the hunting restrictions - 'It's a yuppie thing right now: 'Let's save the black bear.' ' The Jungle Book it isn't.
DISPATCHES (9pm C4) tonight presents a timely repeat of Tom Roberts' film about homeless children in St Petersburg, which last week was voted the Best International Current Affairs Programme of 1992 by the Royal Television Society. As Russia struggles to come to terms with a market economy, some 10,000 children now live rough in its second city.