McLaren are racing to develop ride height control systems that they had thought would be illegal but which Formula One rivals Red Bull seem to be using to their advantage, Martin Whitmarsh said.
"I think there's some evidence that there are ride height control systems which many people wouldn't have thought were permissible," the team boss told BBC after Red Bull swept the front row at the Australian Grand Prix.
"As you can imagine, we are working quite hard on those systems now.
"The original rulings suggested that such systems wouldn't be allowed on cars. [We are] seeing some cars now that seem to me to have those so we've got to have those fitted as quickly as we can," he added. "Hopefully by China, we'll have something on the car."
The Chinese Grand Prix, on April 18, is the fourth round of the season. Red Bull's German Sebastian Vettel has taken pole position in the two races so far this season.
McLaren's Jenson Button will start today's race from fourth place on the grid while his British team mate Lewis Hamilton occupies 11th place after a disappointing qualifying session in Melbourne.