As the superb `Prime Suspect' series reaches part four there is no loss of momentum at all, this in itself a considerable achievement.' Prime Suspect IV: The Lost Child' has the solid supporting cast that we take for granted in these British dramas but of course the beautiful Helen Mirren easily dominates; our eyes never leave her while she's on-screen.

The search for the lost child of the title leads Superintendent Jane Tennison's CID team to a prime suspect who turns out to be a convicted pedophile now living with a single mother and her two young daughters. The insight we are given into the workings of his mind is one of the emotional highlights of this mini-series but it may be too strong for many stomachs.

The action sequences are brilliantly handled with the hand-held camera thrusting us right into the middle of the excitement and there's gripping tension during the climactic siege.

Altogether this is another magnificent police procedural drama.