Arduino as I2C "Master" and "Slave" at the same time?

Hello All Is it possible to use Wireh and configure a program so that the Arduino acts as a "master" device reading and writing into Registers in a slave device on an I2C bus whilst at the same time acting as a "Slave" device receiving data from a third device connected to the bus? A quick search on Google brought up examples of code where the Arduino was either a "master" or a "slave" but none for where it was both at the same time within the same code. Any help appreciated.

Here: http://www.gammon.com.au/i2c

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In fact, the "master" can also act as a slave, since you can have multiple masters on one wire. The example below shows how you can send data from one Arduino to another, whilst waiting for information to be sent from the second back to the first.

Thanks for the reference Nick. It will take me some time to read, understand and digest that so may come back with additional queries once I have done that. (I am a Noob!)