Samsung took a double-hit in its battle against archrival Apple on Tuesday, when the European Union announced it would investigate whether it was illegally trying to hinder competitors and Germany blocked sales of some of its tablet computers.

Samsung Electronics and Apple Inc. are engaged in a strategic war over patents in many countries across the world as they try to draw market share away from each other.

The EU's antitrust watchdog thinks the South Korean company may be overstepping the bounds and launched a formal investigation into whether Samsung is using law suits over key patents on 3G wireless technology to hinder competitors — including Apple.

The European Commission, which is acting as the EU's antitrust enforcer, said it suspected Samsung of not giving other companies fair access to patents it holds on standardized 3G technology for mobile devices — despite committing to do so in 1998.

A spokeswoman for the Commission said the probe also affected tablets such as Apple's newest iPad, which uses standardized wireless 3G technology.

The Commission said that Samsung last year sought legal injunctions against other device makers in several EU states, alleging patent infringement.

Under EU patent rules, a company that hold patents for standardized products are required to license them out indiscriminately at a fair price.

If Samsung is found guilty of unfairly restraining competition, it can be fined up to 10 percent of annual revenue related to the investigation.