I have a good friend who works in UCL biochemistry department and he informed me that after completing a PhD in biochemistry (from manchester university) you can expect a salary of £30k+ in industry, he works in the uni so gets 28k but says his job is less pressurized.
Is his claim about a starting salary in the biochem industry after PhD being above 30k untrue? Or is it pure luck in the job market?

It depends how good you are - don't forget that both his current salary and the industrial one he is quoting include a London weighting of around £2000 or more.

If you type biochemistry in guardian jobs it doesn't show much. There might be more specialised search engines were you can easily test this statement, I would assume.

The Guardian is not renowned for its Biochemistry jobs section.

http://www.reed.co.uk/JobSearchResults.aspx?SearchType=Simple&SearchRoute=20&JobSector=270
The sciencist positions seem to be in £30.000 range.

Try New Scientist or Nature as they have lots of those type of jobs although probably more on the academic side.