New  €100 and €200 notes were released into circulation on Tuesday, completing an overhaul of the currency's paper denominations that is aimed at deterring counterfeiters.

The fresh bills have been changed to have larger numbers in a bolder design, have a satellite hologram, and have been printed in more contrasting shades than the old versions, which had remained the same since they were first introduced in 2002.

"We try always to develop very sophisticated security features because we want to stay far ahead of the counterfeiters," European Central Bank (ECB) Banknotes Director Ton Roos told Reuters news agency.

The new €100 and €200s follow the already overhauled €5, €10, €20, and €50 bills. Old notes will still be valid, but will eventually be collected and replaced by central banks.

€50 notes are the most popular, but €100s are also in high circulation.

Redesigning the bills is part of a larger attempt by the ECB to curtail crime. The bank has discontinued the €500 bill, a measure supporters say will cut back on the financing of terrorism, black market transactions and off-the-books work.

es/rc (dpa, Reuters)