1,263. Other Restrictions of an Onen
196:6 So long as the deceased has not yet been buried, the onen need not remove his shoes and he is permitted to leave his home to tend to needs of the deceased. He is not, however, permitted to sit on a chair or sleep in a bed, and he certainly may not engage in marital relations. He may not bathe or anoint himself, rejoice, extend greetings, cut his hair or study Torah. He is not permitted to work, nor to have others do work for him, even if refraining will cause him to incur a loss. In a case where he would incur a great loss, a Torah authority must be consulted.
196:7 If a person was an onen when it was time to recite the Shema and Shemoneh Esrei, then after burying the deceased more than a quarter of the day had passed so that it was beyond the time for reciting the Shema, he should nevertheless recite it, along with its brachos but without putting on Tefillin. This is only up to one-third of the day; once one-third of the day has passed, he should recite the Shema without its brachos. Shemoneh Esrei may be recited until midday. Musaf on Rosh Chodesh may be recited even after midday because its time is the entire day. He should not recite the Morning brachos except for the three "shelo asanis" and the bracha on Torah study as the time for these is the entire day. He does not recite the rest of the brachos after their time has passed since at the time when he was obligated in them, i.e., in the morning, he was exempt.
If the deceased was buried before one-third of the day had passed and the mourner's house is so far from the cemetery that by the time he reaches home one-third of the day will have passed, then it's better for him to enter some house close to the cemetery - or even outside in a clean place - and to recite Shema and Shemoneh Esrei in the proper time. As soon as they start to cover the deceased with dirt, the relative may recite Shema and Shemoneh Esrei, even though he has not yet entered the status of aveilus (mourning).