The second-hand lens has gone on sale today at MPB Photographic, an online retailer based in Brighton, East Sussex. The price: £99,000 (including VAT).

Dedicated MPB sales staff are poised to take enquiries.

The monster – currently owned by MPB – measures 228x836mm, and carries a filter size of 48mm, according to the website of the Canon Camera Museum.

Originally aimed at sports and wildlife photographers, previous owners are rumoured to include government, law enforcement and surveillance agencies.

‘It would appear that only a small number have fallen into private ownership, resulting in the 1200mm being seldom seen on the used market…’ an MPB spokesperson told Amateur Photographer.

According to Canon, the EF 1200mm f/5.6L USM was launched onto the market in July 1993 when it was billed as the world’s largest interchangeable AF lens for SLRs, in terms of both focal length and maximum aperture.

Its closest focusing distance is 14m.

The giant optic features eight diaphragm blades and a ‘one-touch’ revolving mechanism for ‘quick switching’ between vertical and horizontal formats.

At launch it cost 9.8 million yen (around £57,000 at today’s exchange rates), with case and hood, adds the Canon website.

‘Extremely sharp, professional-quality images are realised through use of two large-diameter artificial crystal fluorite lens elements (3rd and 6th) that thoroughly eliminate secondary spectrum.’

MPB’s founding director Matt Barker says his firm has experienced ‘exceptional growth’ since it launched in 2006, adding that acquiring this lens ‘embodies this success’.

For details, call MPB Photographic on 0845 459 0101 or see the listing here, which is due to go live this lunchtime.

We’ve seen the Canon EF 1200mm before, in our round-up of 6 of the most ridiculous lenses ever made.