Mystery white marks on Moss’ jeans... has she been powdering her nose again?

Having left London restaurant China Tang at 9.30pm, she didn't arrive home until midnight - staggering out of the vehicle with specks of what looks like white powder down her jeans.

Scroll down for more

Riddle: Kate Moss arrives home with the white marks (circled) visible on her jeans

Moss, who this week is celebrating the runaway success of her new Topshop range, had been dining with friends at China Tang restaurant in London's Dorchester hotel.

But what she got up to in the two-and-a-half hours between leaving Park Lane and arriving at her north London home remains a mystery.

Kate Moss leaves London's China Tang restaurant with Sir Philip Green after the launch of her clothing range

Wearing her trademark waistcoat and skinny black jeans, she climbed into the car looking calm and serious.

By the time she got out, without the waistcoat, she seemed a little the worse for wear.

After the scandal two years ago, when a photograph allegedly showed Moss snorting cocaine, you might think she would have been extra careful with the paparazzi about.

But she did not notice the powder on her jeans, which could be misconstrued.

Since the notoriety Moss, 33, has picked up more modelling offers than ever and earned three times what she did before, bumping her fortune up to nearly £50 million.

China Tang has become a favourite venue for Kate.

Earlier this week she dined there with Topshop boss Sir Philip Green - but that time she simply fell asleep on the way home.

Reports say thousands of Kate Moss TopShop items are languishing unsold on auction site eBay as shoppers avoid sellers attempts to cash in on the sold out range.

Although some dresses were attracting bids of £200 or more, there were scores of items failing to prompt any activity.

One advert for the special edition red dress the supermodel wore herself when posing in the store's display window on Monday night has received one bid of a whopping £250.

The model's collection went on sales exclusively in France yesterday at 11am in Paris style emporium Colette, and by 1pm, was virtually sold out.

Kate Moss for Topshop will also start retailing next week at Corso Como in Milan and at Barneys New York, and is available on Topshop's Web site.