RAPAPORT... Grib Diamonds, which markets rough from one of Russia's largest mines, has canceled next month's auction after a bank blocked customers' payments at a previous sale."In order to avoid a similar situation during the next auction, and due to the fact that Grib Diamonds has no influence on the payment routes of its clients, it was decided to postpone the upcoming auction in Dubai," said Antony Dear, head of sales at Grib Diamonds, in an email to Rapaport News Tuesday.The Belgium-based company sells production from the Grib mine in the Arkhangelsk region. AGD Diamonds, which is privately owned, bought the deposit from Russian energy giant Lukoil for $1.45 billion in 2017. While sales have traditionally taken place in Antwerp, Grib Diamonds has held several auctions in Dubai this year.At the most recent one in early September, a bank prevented some clients' payments from being processed, Rapaport News understands. The company did not disclose the financial institution's identity."Some of our customers recently faced an issue with a particular correspondent bank blocking payments to Grib Diamonds," Dear noted. "The reason why the payments are blocked by this particular correspondent bank is at present unknown to us. All other correspondent banks processed payments without delay."It's unclear whether the payment issue is directly related to Western sanctions on Russia. The Swift payment system disconnected select Russian banks following the start of Russia's war in Ukraine earlier this year. Completing payments to Russian companies such as diamond miner Alrosa has become more difficult since then.Dear said the company was working with its external legal adviser, which would initiate communication with the bank in question and "provide all the necessary information [or] evidence required to settle its concerns."Image: Rough diamonds. (Grib Diamonds)