Following seven-figure investment from Qatari magnate, former Banksy agent plans to expand secondary market business with artists including Basquiat and Haring

Inaugural December event brings city's Old Master dealers out from the shadows with exhibitions at more than 30 galleries

Sportswear company accepts it infringed trademark with trainers distributed during Art Basel in Miami Beach 2016

Export bar placed on plush piece with asking price of more than £480,000

US artist's new work examines migration, madness and colonisation in contemporary America

A growing number of women are appearing on the rostrum and taking senior auctioneer roles

Our pick of highlights from upcoming auctions

Thomas Campbell posted an image of the Salvator Mundi before conservation, triggering a row with its former co-owner Robert Simon and Christie’s Loic Gouzer

BUM was created just before Boty died of cancer aged 28 in 1966

Franz von Stuck’s portrait of two girls was due to be sold at Van Ham

Our pick of highlights from upcoming auctions

Local rivalry between Düsseldorf and Cologne was put to bed as the inaugural fair opened

Aboriginal work, Earth’s Creation I, was shown at the 2015 Venice Biennale

Capping an epic week of auctions, solid results featuring records for female artists and a Ferrari bode well for market's future—so long as it doesn't overheat

Dorotheum sale piques interest, pre-empting centenary of the artist’s death next year

Despite buy-ins, the sale saw several strong prices and records below the dizzy height of $450.3m for Leonardo da Vinci's Salvator Mundi

Price makes it the most expensive painting of all time

In a city of artists but few collectors, an overhauled fair hopes to drum up trade against competition from established Art Cologne and a new Düsseldorf event

New York sale results boosted by strong Asian and Russian buying, and shored up by guarantees

Where a museum's Rockwells had sparked interest in a flagging category, the removal of key lots from the sale dampened spirits

Painting is being presented by Christie’s as the “Holy Grail of Old Master paintings”

Pre-auction assessment offers evidence that painting is original Leonardo but also reveals problems posed by painting’s wooden panel

Salvator Mundi will break Old Master auction record as seller dispute rumbles on

Van Ham to offer Franz von Stuck portrait in 17 November sale

Auctioneer Claude Aguttes will sell the collection of historic books and manuscripts across 300 sales over at least six years as part of liquidation

Pent-up demand for top material kicks off New York's key auction week, with a $81.3m Van Gogh and records for Léger, Magritte, Man Ray and Vuillard

Our pick of this month's most interesting auctions

Proceeds from Berlin sale, which also includes works by Rosemarie Trockel and Tomás Saraceno, will benefit Kayany Foundation

The octogenarian artist is in ascendance, with a solo show opening at the Serpentine later this month